Chromosome number variations in newly synthesized hexaploid wheats spontaneously derived from self-fertilization ofTriticum carthlicumnevski /aegilops tauschiicoss. F1hybrids

Abstract

This study was aimed at elucidating numerical variation of chromosomes in newly synthesized hexaploid wheats. We carried out artificial crosses between Triticum carthlicum (2n = 4x = 28, AABB) as female parent and Aegilops tauschii (2n = 2x = 14, DD) as male parent, obtaining intergeneric F1 hybrids (2n = 3x = 21, ABD). After self-fertilization of the F1 hybrids having 21 somatic chromosomes, we obtained F2 seeds (synthetic hexaploid wheats), and determined their somatic chromosome number. Of the expected 150 cross combinations of F1 hybrids between six strains of T. carthlicum and 25 strains of Ae. tauschii, 67 cross combinations of synthetic hexaploid wheats were obtained. Compared to strains of Ae. tauschii ssp. tauschii, those of Ae. tauschii ssp. strangulata produced synthetic hexaploid wheats showing euploidy with a high frequency. In addition, among strains of Ae. tauchii ssp. tauschii, those from Iran contributed more to the production of synthetic hexaploid wheats showing euploidy than those from...